It is proposed to continue work in the field of the Physiology of the Central Nervous System, and its relation to behavior, along several lines: (1) To study the functional properties of striate and pre-striate neurons in the cerebral cortex of waking, behaving monkeys, particularly the neuronal mechanisms in depth perception and stereopsis. A behavioral study is planned of the monkey's capacity for depth discrimination, in relation to the eye movements that occur during acquisition and observation of random-dot stereograms. (2) To study further the light-sensitive neurons of area 7 of the waking, behaving monkey, in particular to define their sensitivities to moving stimuli in a quantitative manner. In addition, we intend to continue our studies of saccade, fixation, and projection neurons, and of the latter two in total darkness. (3) To initiate a new series of studies of the parietal and frontal neocortex, as regards the neuronal mechanisms in coordinated visuo-motor guidance of hand and arm towards targets of interest. (4) To continue studies of the basal ganglia and related subcortical regions of the brain in waking monkeys trained to execute motor tasks.